With advances in information communication technology in recent years, a variety of apparatuses are being connected to and used in networks. However, there are apparatuses that are not necessarily installed in locations for which a power supply is readily available, such as various types of sensors for the detection of temperature and the quantity of light in factories or buildings or for detecting the opened or closed state of doors and windows as well as monitor cameras and wireless LAN (Local Area Network) access points. In addition, there are some kinds of devices, connecting which it was not necessary to consider a power supply (such as a fixed-line phone that is supplied with power from the telephone line), but which have come to require a power supply due to the additional functions for LAN, such as an IP phone.
Known methods of enabling the supply of power while enabling data communication with various types of such apparatuses include, for example, PoE (Power over Ethernet).
PoE is a technology that enables the transmission and reception of data and power supply by way of a predetermined cable but is not a technology for controlling the state (ON/OFF of the power supply, transition to sleep state, recovery from sleep state, regardless of whether the main functions of an apparatus are operating, etc.) of each apparatus. In order to enable the control of the state of each controlled apparatus, the state of each controlled apparatus must be communicated to the control device. Examples of technology that can be used in this communication of states include LLDP (Link Layer Discovery Protocol) and CAN (Controller Area Network).
In addition, although not standardized such as LLDP and CAN, a method that monitors the state changes of a plurality of printers to ease congestion of traffic on a network is disclosed in Patent Literature 1. In addition, the acquisition of the operating state of a residential apparatus to transmit control information and bring about operation when the residential apparatus can be remotely operated is disclosed in Patent Literature 2. Still further, Patent Literature 3 discloses a technology for enabling the remote control of an apparatus by way of a communication network even when turning OFF the power supply has caused the IP address to be assigned to another apparatus.
The above-described LLDP is a protocol for communicating information such as the type and setting information of a network apparatus or terminal to a neighboring apparatus, but even though a control apparatus is able to collect information of a controlled apparatus, it is not capable of controlling states that include turning ON and OFF the power source of a controlled apparatus.
Still further, the above-described CAN or the technology described in Patent Literatures 1-3 is basically technology for controlling the operation of a controlled apparatus when the power source of the controlled apparatuses is ON and does not control states that include turning ON and OFF the power source of the controlled apparatus. Still further, CAN requires the assignment of a characteristic identifier (ID) to a controlled apparatus through human operation, raising the problem of the extra time and trouble required for re-assigning an ID when a particular controlled apparatus is moved and used in a different network that corresponds to CAN.